Dual fluid single rotor turbine

ABSTRACT

A method and apparatus for generating power in a rotating turbine wheel, wherein two working fluids are circulated within a rotating turbine rotor with a third fluid providing a supply of heat, and also serving as a heat sink. Said two working fluids are compressed and are in heat exchange relationship during and after compression; after compression, said working fluids are expanded. Work is required by said fluids during said compression and acceleration, and work is obtained from said fluids during said expansion and deceleration. Typical fluids for use are carbon dioxide as one of the working fluids releasing heat during said compression and receiving heat from said heating fluid, and nitrogen as the other working fluid receiving heat during said compression and being cooled by releasing heat to said heat sink. Said heating fluid may be water. Alternately, a separate heating fluid, and a separate coolant may be used.

United States Patent Eskeli DUAL FLUID SINGLE ROTOR TURBINE MichaelEskeli, 6220 Orchid Lane, Dallas, Tex. 75230 Filed: Nov. 1, 1973 Appl.No.: 411,919

Related U.S. Application Data Continuation-impart of Ser. No. 410,985,Oct. 30, 1973, Pat. No. 3,861,147.

Inventor:

References Cited UNITED STATES PATENTS 10/1948 Roebuck 165/88 2,522,7819/1950 Exner 62/499 2,529,765 11/1950 Exner 62/499 FOREIGN PATENTS ORAPPLICATIONS 605,618 7/1948 United Kingdom 415/179 an O r 19 COO [ 51Nov. 18,1975

Primary E.raminerAlbert W. Davis, Jr. Assistant Examiner-Sheldon Richter1 1 ABSIRACT A method and apparatus for generating power in a rotatingturbine wheel, wherein two working fluids are circulated within arotating turbine rotor with a third fluid providing a supply of heat,and also serving as a heat sink. Said two working fluids are compressedand are in heat exchange relationship during and after compression;after compression, said working fluids are expanded. Work is required bysaid fluids during said compression and acceleration, and work isobtained from said fluids during said expansion and deceleration.Typical fluids for use are carbon dioxide as one of the working fluidsreleasing heat during said compression and receiving heat from saidheating fluid, and nitrogen as the other working fluid receiving heatduring said compression and being cooled by releasing heat to said heatsink. Said heating fluid may be water. Alternately, a separate heatingfluid, and a separate coolant may be used.

1 Claim, 6 Drawing Figures DUAL FLUID SINGLE ROTOR TURBINE CROSSREFERENCES TO RELATED APPLICATIONS This application is acontinuation-in-part application of Sealed Single Rotor Turbine, filedOct. 30, I973, Ser. No. 410,985, now US. Pat. No. 3,861,147.

This invention relates generally to turbines for generating powerwherein a working fluid is passed from higher energy level to lowerenergy level generating said power in a rotating rotor, with heataddition and cooling being provided within said rotor.

There have been various types of turbines previously; in some of these,a fluid is accelerated in a stationary nozzle and then passed to vanesmounted on a rotating rotor where the kineticenergy contained by saidfluid after said acceleration is converted to power.

These conventional turbines require a pressurized fluid source for theiroperation, such as steam, thus making the entire power generating systemcostly.

FIG. 1 is a cross section of the turbine power generator, and

FIG. 2 is an end view of the unit shown in FIG. 1, with portions removedto show interior details; 7

FIG. 3 is a cross section of another form of the turbine, and FIG. 4 isan end view of the unit shown in FIG. 3, with portions removed to showinterior details;

FIG. 5 is a pressure-enthalpy diagram with a work cycle illustratedthereon for the heat exchanger part of the turbine, and

FIG. 6 is a pressure-enthalpy diagram for power generating part of theturbine with a work cycle illustrated thereon.

It is an object of this invention to provide a power generating turbinewherein a heat exchanger portion is provided to elevate temperature ofthe available heat, and then pass this heat to a turbine to generatepower; all this being combined within a single rotor. Further, it is anobject of this invention to provide a turbine wherein the turbine rotoris constructed in such manner as to allow placement of said rotor withinan evacuated casing thus reducing friction losses on said rotor. It isalso an object of this invention to provide a power generating turbinewherein low temperature heat source may be used to generate power.

The turbine of this invention may have either three or four fluids beingcirculated within the rotor. In the following, the fluid being sealedwithin one portion of the rotor, and being the fluidgenerating thepower, is the first fluid; the fluid being sealed within another portionof the rotor and being used to increase the temperature of the availableheat, is the second fluid; the fluid providing the heating and whichalso may be used for cooling, is the third fluid; and the fluid beingused exclusively for cooling, is the fourth fluid.

Functionally, the first fluid and the second fluid are compressed bycentrifugal action by the rotor on the fluids with accompanyingtemperature increase for both fluids; also, these two fluids are in heatexchange relationship during this compression. Said first fluid and saidsecond fluid are selected to provide for greater temperature increasefor said second fluid, so that heat is transferred from said secondfluid to said first fluid during and after compression of said firstfluid. After such compression and heat removal, said second fluid isallowed to expand and during and after expansion heat is added to saidsecond fluid from a lower temperature heat source, after which saidsecond fluid is passed to be compressed thus completing the cycle. Saidfirst fluid is allowed to expand after said heat addition, and duringsuch expansion work is produced, with accompanying temperature andpressure decrease, and after such expansion, the first fluid is cooledby removing heat, after which said first fluid is passed to becompressed again thus completing the cycle. Part of the work generatedby said first fluid is needed to rotate said rotor section for saidsecond fluid, and the remainder is available to be passed out as theuseful work output of the turbine.

Referring to FIG. 1, therein is shown a cross section of one form of theturbine. 10 is casing supporting bearings and seals 19 and 29, and shaft20. Said first fluid is compressed within rotor 11, with vanes 36assuring that said first fluid will rotate with said rotor, and withheat being added to said first fluid from said second fluid through heatconductive wall 27 and with said vanes 36 also serving as heat exchangemembers. After compression, said first fluid is passed through nozzles23 in forward direction thus providing for said first fluid an absolutetangential velocity that is greater than the tangential velocity of saidnozzles, after which said first fluid will enter to the expansion sideof said rotor with vanes 15 .assuring that said first fluid will rotatewith said rotor and for receiving the work associated with decelerationof said first fluid. After expansion, the first fluid temperature isusually too high to permit passage of said first fluid to saidcompression side of the rotor, and thus a cooling heat exchanger 17 isprovided to reduce the first fluid temperature to a predetermined value.After such cooling, said first fluid is passed to said compression side,for compression in the outward passages for said first fluid. 14 is adividing wall. The second fluid is compressed in its outward extendingpassageways, with vanes 25 assuring that said second fluid will rotatewith said rotor, and also serving as heat exchange members. Heat isremoved from said second fluid during said compression, and aftercompression, said second fluid is passed through nozzles 12 in backwarddirection thus providing for said second fluid an absolute tangentialvelocity that is less than the tangential velocity of said nozzles 12.Said second fluid is then passed to space 34 and from there to inwardextending second fluid passageways, where vanes 33 will assure that saidsecond fluid will rotate with said rotor and also for receiving the workassociated with deceleration of said second fluid. During said expansionand deceleration, heat is added to said second fluid to maintain itstemperature at a predetermined value; this heat addition may alsocontinue after said expansion. After said heat addition, said secondfluid is passed to be compressed again, by vanes 25. The third fluidenters rotor 11 shaft 20 via opening 21, and is passed to heat exchanger17, arranged to be in counterflow with said first fluid; after passingthrough said heat exchanger 17, said third fluid will pass along passage22 to conduit 35 to heat exchanger 32, where said third fluid is inparallel flow with said second fluid; after that said third fluid InFIG. 2, an end view of the unit illustrated in FIG. 1, is shown, withportions removed to show interior details. is casing, 1 1 is rotor, 12is second fluid nozzles, 33 is vanes, 34 is fluid space, 32 is heatingheat exchanger, is shaft, 37 indicates direction of rotation for therotor, 13 is fluid space, 36 are vanes, 23 are nozzles, 14 is divider,15 are vanes. It should be noted that nozzles 12 are similar in crosssection to nozzles 23.

In FIG. 3, another form of the turbine is shown. In this turbine, theouter rotor cavity contains said first fluid, and inner cavity containssaid second fluid, with the function of both fluids being similar tothat described hereinbefore for the unit shown in FIG. 1. 55 is casing,54 is rotor, 52 and 66 are bearings and seals supporting rotor shaft 50,51 and 67 are entry and exit, respectively, for third fluid, 68 and 70are entry and exit respectively, for fourth fluid, 69 is third fluidpassage. First fluid leaves cooling heat exchanger 65 and is compressedwith vanes 63 assuring that said first fluid will rotate with said rotorand heat being added through wall 73 and vanes 63 also serving as heatexchange members. After compression and heat addition, said first fluidpasses through nozzles 62 oriented to discharge forward thus providingfor said first fluid an absolute tangential velocity that is greaterthan the tangential velocity of said nozzles 62; after which said firstfluid enters space 61 and then passes to the expansion side of saidrotor to inward extending fluid passages with vanes 56 assuring thatsaid first fluid will rotate with said rotor and for receiving the workassociated with deceleration of said first fluid; after which said firstfluid is passed to heat exchanger 65, and after cooling, passed to saidoutward extending passageways for said compression. Said second fluid iscompressed with accompanying pressure and temperature increase by saidrotor with vanes 60 assuring that said second fluid will rotate withsaid rotor; with heat being transferred to said first fluid during saidcompression and with vanes 60 also serving as heat exchange members;after said compression said second fluid is passed through nozzles 59 toexpansion side of said rotor to space 58, and from there to inwardextending passageways where vanes 72 will assure that said second fluidwill rotate with said rotor and for receiving the work associated withsaid deceleration of said second fluid; during said expansion heat isadded to said second fluid in heat exchanger 64, after which said secondfluid is passed to said outwardly extending fluid passages for saidcompression. 67 is dividing wall, 68 is casing vent opening into which avacuum pump may be connected, 57 is dividing wall.

In FIG. 4, an end view of the unit shown in FIG. 3 is illustrated, withportions removed to show interior details. 55 is casing, 56 are vanes,57 is dividing wall, 62 are nozzles, 63 are vanes, 7 1 indicatesdirection of rotation for rotor, 50 is shaft, 63 are vanes and heatexchange members, 64 is heat exchanger for heating, 72 are vanes, 58 isfluid space, 59 are nozzles for second fluid, 56 are vanes, 54 is rotor.

In FIG. 5, a pressure-enthalpy diagram is shown with a work cycleillustrated thereon for said second fluid. 70 is pressure line and 71 isenthalpy line, 72 are constant enthalpy lines, 73 are constant pressurelines and 74 are constant entropy lines. Compression with heat removalis shown by line 75 to 77, and expansion at constant entropy is shown byline 77 to 76, and expansion with heat addition is shown by line 76 to75, thus completing the cycle.

In FIG. 6, a typical pressure-enthalpy diagram is shown for said firstfluid, with line 80 being pressure line, and line 81 being the enthalpyline. 82 is constant enthalpy, 83 is constant pressure and 84 isconstant entropy. The first fluid is compressed from 85 to 86 withconstant entropy, and then heat is added from 86 to 87, after which thefluid is expanded isentropically from 87 to 88 and then heat is removedfrom 88 to 85 thus completing the work cycle.

In operation, a suitable amount of first fluid is inclosed within itscavity in the rotor, and also a suitable amount of said second fluid isinclosed within its cavity within the rotor. The rotor is started byusing a suitable starter, and brought to its operating speed. Thecirculation of the various fluids within the rotor passages is asdescribed hereinbeforc. Heat is supplied to the turbine by said thirdfluid. Cooling for the first fluid is provided by said third or saidfourth fluid. Said third and fourth fluids are supplied from externalsources. Work is produced by said turbine, and said work is then passedto an external load.

The first fluid and the second fluid are selected to have differentamounts of temperature increase, as noted hereinbeforc. Both fluids areusually gaseous. In some instances, it may be possible to operate saidturbine by using as a first fluid and as a second fluid the same fluidat different initial pressures. As an example, said first fluid may benitrogen, at 15 psia pressure at center during operation, and saidsecond fluid may be carbon dioxide, at psia pressure at area nearestrotor center. The selection of these two fluids must be carefully madeto have an operable unit, and the physical properties at the pressuresand temperatures contemplated must be well known for the first andsecond fluids. Generally, said first fluid is selected to have bestpossible work output for the operating conditions; the said first fluidshould be selected using tables for real gases, or by experimentation.Similarly, the second fluid is selected using tables for real gases orby experimentation, to have a gas with a greater temperature increasewithin rotor than for said first fluid, while at the same time having alow work input within said rotor during operation. The two fluids,carbon dioxide and nitrogen meet these conditions. Other fluids that maybe used as said first fluid are air, oxygen, carbon monoxide, andothers. For said second fluid, various hydrocarbons, halogenatedhydrocarbons, nitrogen and other fluids may be used.

The said third fluid may be either a gas or a liquid. Normally, a liquidwill be suitable, and water may be used.

The function of the power generating portion of the turbine is asfollows: Said first fluid is accelerated and compressed with sometemperature increase of its own, and additional increase in enthalpy andtemperature is provided by the heat being transferred from said secondfluid. This heat addition will increase the available energy level ofsaid first fluid and decrease its density, so that pressure build-up onthe expansion side due to centrifugal force is reduced, thus allowingfor a larger radius for vanes 15, FIG. 1, while still providingsufficient pressure differential to maintain first fluid flow in theindicated direction. Thus, due to the greater initial tip velocity ofthe rotor vanes on the expansion side, more work is transferred to rotorvia vanes 15, due to greater amount of deceleration, than is required toaccelerate said first fluid in the compression side, where the firstfluid density is greater. Thus, the circulation of said first fluidwithin said rotor cavity is due to density differentials created byadditions and subtractions of heat, while the work input and output aredue to amounts of acceleration and deceleration of said first fluidwithin said rotor; noting that part of the acceleration is done innozzles where only a portion of the reaction is transferred to saidnozzles and rotor, and the first fluid is free of restraints after saidpassage through said nozzles. Note the space free of vanes in eachinstance after the fluid leaves a set of nozzles.

Various controls and governors are used with the device of thisinvention. They do not form a part of this invention and are not furtherdescribed herein.

Vanes l5 and vanes in FIG. 1, are normally radial; however, they may bemade curved, if desired. Similarly, vanes 56 and 60 in FIG. 3, arenormally radial, but they may be made curved if desired. The rotors aremade of heavy material section as shown, and the rotor walls are usuallythicker near rotor center to provide for needed strength for high speedrotation. The nozzles 59 and 12, are similar in construction to nozzles62 and 23. The heat exchanger are usually made from tubing and arespiral in form to provide needed flow patterns shown in figures. Therotor of FIG. 3 may have thermal insulation as required, similar to FIG.1.

What is claimed is:

1. A power generator comprising:

a. a means for rotatably supporting a shaft;

b. a shaft;

c. a rotor supported by said shaft so as to rotate in unison therewith,said rotor having:

i. a turbine section comprising a first outward extending passageway anda first inward extending passageway for a first fluid with said outwardextending first fluid passageway and said inward extending first fluidpassageway being connected at their outward ends and at their inwardends for circulation of said first fluid, said outward extending firstfluid passageway having a set of first nozzles for passing said firstfluid, said first fluid passageways having a first heat exchanger meansfor adding heat into said first fluid and said first fluid passagewayshaving a second heat exchanger means for removing heat from said firstfluid;

a heat exchanger section comprising a second outward extendingpassageway and a second inward extending passageway for a second fluidwith said outward extending second fluid passageway and said inwardextending second fluid passageway being connected at their inward endsand their outward ends for circulation of said second fluid, said outerends of said second outward extending second fluid passageways havingnozzles at their outward ends for passing said second fluid into saidinward extending second fluid passageways, said second fluid passagewaysbeing provided with a third heat exchanger means for adding heat intosaid second fluid, and said second fluid passageways being provided witha fourth heat exchanger means for transferring heat from said secondfluid into said first heat exchanger means and from there into saidfirstfluid.

1. A power generator comprising: a. a means for rotatably supporting ashaft; b. a shaft; c. a rotor supported by said shaft so as to rotate inunison therewith, said rotor having: i. a turbine section comprising afirst outward extending passageway and a first inward extendingpassageway for a first fluid with said outward extending first fluidpassageway and said inward extending first fluid passageway beingconnected at their outward ends and at their inward ends for circulationof said first fluid, said outward extending first fluid passagewayhaving a set of first nozzles for passing said first fluid, said firstfluid passageways having a first heat exchanger means for adding heatinto said first fluid and said first fluid passageways having a secondheat exchanger means for removing heat from said first fluid; ii. a heatexchanger section comprising a second outward extending passageway and asecond inward extending passageway for a second fluid with said outwardextending second fluid passageway and said inward extending second fluidpassageway being connected at their inward ends and their outward endsfor circulation of said second fluid, said outer ends of said secondoutward extending second fluid passageways having nozzles at theiroutward ends for passing said second fluid into said inward extendingsecond fluid passageways, said second fluid passageways being providedwith a third heat exchanger means for adding heat into said secondfluid, and said second fluid passageways being provided with a fourthheat exchanger means for transferring heat from said second fluid intosaid first heat exchanger means and from there into said first fluid.